Terracotta Discussion Forums (LEGACY READ-ONLY ARCHIVE)

Hi there,

My app uses Spring+Hibernate for lifecycle, persistence, etc. I have a few uninformed questions in regards to how TVS/DSO/HA-JDBC would fit into such an environment:

0) Are DSO and HA-JDBC known to play well with Hibernate and/or Spring? If so, is any particular combination of version(s) better? (Note that Hibernate already does its own bytecode instrumentation by default)

1) DSO seems like it would take the place of Hibernate's "second-level cache" without needing to implement their cache API; does this mesh with your understanding?

2) Can I spin up a TVS server as a Spring bean as part of my server's startup process, or does it have to be the main thread?

3) Is it possible to use DSO without changing my JVM's bootclasspath? For example, I'd prefer the TVS environment to apply only to a single web-app. Note that Hibernate doesn't need to modify the bootclasspath to use bytecode instrumentation.

4) It's a little worrying to see java., javax., sun. etc. classes in dso-boot.jar. Is there a lighter-weight way to do it?

Thanks!

-0xe1a

Hello. I'll do my best to answer each of your questions

0) Since HA-JDBC is just a JDBC driver, we believe it should work fine. We are still spinning up our own certification tests for this.

DSO, on the other hand, does have a few known issues with Hibernate and Spring - we're in the process of ironing them out now. As you suggest, it's a matter of making sure that the various bytecode instrumentors play well together.

1) It does mesh with our understanding - this is something we are actively exploring. As mentioned above, though, we still have a little bit of work left before we can get there.

2) This is not possible today, but we are working to get there.

3) Right, point taken. It's a bit more challenging for us because we have to be able to instrument any class, not necessarily just those in your application. We are looking to see if we can come up with a solution using 1.5's hotswappable classes.

4) Much of what you see in there are essentially hand-tuned optimizations for some commonly-used classes. And again, we're looking to see if we can hotswap some of the things in there to be more lightweight.

Hope that helps, let me know if you have any other questions.

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Patrick Calahan
Product Manager
Terracotta, Inc.